Detachable crank and counterbalance for oil well pumping machines



Jan. 1, 1935. R. B. DUNLAP 1,986,188

DETACHABLE CRANK AND COUNTERBALANCE FOR OIL WELL PUMPING MACHINES Filed Nov. 5, 1932 gwuemto a ROBTB DUNLAP.

Patenteci Jan. 1,1935 7 a I a 1 V UNITED STATES; OFFICE c 86 88, I

. DETACHABLE CRANK AND- OOUNTERBAL v. ANCE FORHIOIL WELLrrTUMPING 'MA-- CHINES 1 i'.:-f-:--. J

RobertBoyd n ni mshivp rt, La. ApplicationNoveniber Serial No.' i41 340 L t. i

The invention relates to an improvement in by any suitable source 'of'power andmay have combination cranks and counterbalances for at mountedthereon a bandwheel suchas 9, or it may. tachment to the crank shaft of well pumping project from any of the standard formsofreducunits. tion gearsgenerally designated in the field as a 5 One of the objects of the invention is to propumpingunit. The crank shaft 8 is mounted 5 vide a counterbalance and crank arm which may upon the usual jack post 10, which serves as a be quickly and readily attached or detached from bearing to support it for rotation. V I the crankshaft; so that the shaft will be free to 1 The invention particularly relates to the conrotate in performing the servicing operations struction of the crank arm 7 and the associated 10 upon the well. v 7 parts whereby'the crank'arm maybe attached or 10 Another object of the invention is toprovide a detachedfromthe crank shaft '8. Fig.1 shows crank arm which includes a counterbalance which the crank arm 7 as including the frame 15, which may be quickly attached 1 or detached from the; is provided with an edge rib 1 6 and web 17, which crank shaft by'clamping the crank arin to the is cutaway, as at 18,] to lessen theweight'adjashaft with a releasable crank.

5 Claims,

cent the'centercfrotation. 15 Another object of the invention is to provide a The frame 15 is, however, provided with the crank arm which is-adapted to be clamped to the shaft receiving opening near itscenter. This crank shaft by a pivoted lever construction which opening 20 mayor may not be provided witha may be firmly bolted in position to compel the plurality of transverse slots or grooves 21, which 20 crank arm to rotate with the crank shaft as a" are adaptedto receive the keys or clutch faces 22. 20 unit. Thesekeysmay bemoved into the grooves later- Another object of the invention is 'to provide a allyand are adapted to project slightly above the crank arm having alever construction whichper face; 23 of theopening so that they will abut mits a mechanical advantage in clamping the against the bushing 24., which is keyed to the 25 crank arm to the crank shaft. I

Other and further objects of the invention will been shown but iti s understood that any desired be readily apparent when the following descrip-' number-may be provided. tion is considered in connection with the ac'com Irrorder to clamp the frame to the: crank shaft p-anying drawing wherein: l 8=and the bushing 251 a leveror clamp 25 has been Fig. 1 is a side elevation of the invention approvided. Thislever is preferably quite massive 30 plied to a crank shaft and clamped in its operatandis arranged to receive the pivotpin 26, which m position. q .is' carried by the spaced'flanges'27. on the frame Fig. 2 is an edgeview showing the construction 151* the form' of a tongue and groove 7 of Fig. 1. ccns'tructionwherein the tongue 28 is formed as Fig. 3 is a sectional view taken on the line 3 -3 part of the'lever 25,'whi1e the groove is that space 35 of Fig; 1 and looking in the direction of the between the twoflanges 27 on the frame. Thus, arrows. I v I r i the-lever or arm 25 is arranged to pivot with Fig. 4 is a diagrammatic view of the invention respect to the-frame 15; The arm 25 carries a key applied to an oil well pumping mechanism. 30; which is similar to that of the keys 22, as seen crank shaftS; at 26'. Three of these keys 22 have 25 40 The invention will be best understood by having inFig. 1'. The keys. 22 and 30 are spaced on thirds 40"" reference to Fig.=1 wherein the pumping mecliaof the periphery of the bushing 24. When it is" I nism is indicated generally at 2' and includes a desired to-attach the combination crank arm and walking beam 3, which is connected to thepump counterweight to the crank shaft the arm 25 is rods 4, which-in turn extend through the-well pivoted about'the pin 26 in an anticlockwise di- "head 5 to the pump,- which is located near the rection-asviewed in Fig. 1, untilthe arm is car- 45 bottom of the well. Reciprocation of the string ried around to the position illustrated. 7 of rods 4 causes operation of the pumpto lift the The end of the armis provided with aslot 35, fluid from the well. The rods 4am reciprocated Y which'receives the bolt or latching device 36., A by the oscillation or rocking movement of the nut 37threaded on with the bolt 36 maybe turned 5 walking beam 3. 'The'pitman 6 is connected'to down-to move the leverarm toward the frame.

the walking beam to cause" rocking movement v2 This movement causes the key 30 to force the thereof and the pitman is in turn caused'to'move bushing 24 against the keys 22 carried by the by being connected to the crank arm 7, which is frame until the crank arm and counterweight are mounted for rotation with the crankshaft 8. securely latched or clamped to the bushing and The crank shaft 8-itis to be understood is rotated crank shaft; The bolt'36 is pivotally mounted in 55 with a plurality of openings 40, which are ar-..

ranged to receive the wrist pin 41'by 'whic'h the pitman 6 is connected to the crank arm in a manner well known in the art. A plurality of the openings 40 are provided morder'to jobtain differe ent length strokes for the puinping mechalnism... The frame 15 has an enlarged outer end 45,

which is shown in Fig. 2 as being somewhat thickened in order to provide a massive weight which will serve to counterbalance the string of rods ii and the column of fluid in the well. Because of the walking beam 3 the crank arm is-travermg downwardlywhen the rods and column-offluid-g are moving upwardly. ,Therefore, if a -counterweight is provided it should be moving down-. wardly to help raise thefluid and to move upwardly to resiststhe' falling of the fluid on they reverse stroke.

The amount of counterweight-necessary onany particular well is dependentupon a numbenof variable conditions, suchasthe depth of the well,

the specific gravity of the fluid, the friction-of; the pump, and the straightness of the hole. The

body 45 will, therefore, be provided with openings or connections for any desired number of additional weights which may be attached or detached to the frame in order to obtain theproper amount I of counterbalance. In some instances it is desirable to have the center of gravity of the counterweight ahead or behind the center line of the wrist pin so that the weight will either be applied ahead or behind the ends of thepumping stroke.

With this inmind, the weightsmaybe attached to either the-right or the .lefthand side of the frame as viewed in Fig. l. e

fI-heattaching of weights to the-frame in this manner is old and well knownin the art and does not constitute any part of the 'presentinvention and for this reason the same have-not been shown in the drawing.

circular members'which fit into the grooves 21,

which areslightly more than a half circle so that the pins will not drop out of position when the crank arm is disconnectedQit is to be understood that-they may be in the form of keys orshoes of any desired shape or configuration, the principal feature being to; obtain a clamping action on the" bushing 24 so that thecrank arm and crank shaft.

will be compelled to rotate as a unit.

It; is contemplated that a suitable support may be positioned below the crank shaftto receive the frame, crank arm and counterweight construction when itis released from its position on the crank arm. "The lever 25 is of advantagej'in' manipulating this massive construction "because when the nut 37 is'released the arm' '25 will move upwardly as viewed in Fig. 1, so that the frame and counterweights will be gradually lowered away from the crank shaft. The inside'face 50 of the clamping'arm 25 will thus cam over. the top curvedsurface of the: bushing and, by controlling; the movement of this lever 25* as it is being -re-- leased, servesto control the lowering movement of the counterweight and crank arm, because -of the great mechanical advantage obtainedfrom While the keys'22 and 3 have been shown this lever construction it is possible for a single man to attach or detach the counterbalance construction. The present combination crank and counterbalance may be clamped to the crank shaft in any radial position.

When it is desired to attach the construction the weight is merely positioned beneath the crank shaft and the lever 25 carried around the crank shaftin an anticlockwise direction as viewed in Fig. 1'. By pressing upon this lever the entire can beista'rted'onto 'thebolt 36. While the bOlt i 36 hasibee'n shown'as merely projecting through the nut 37 a short dis't'ance, it is to be understood that this bolt may be of any desired length so that the nut 37' may be used to draw the lever arm aroundi the cran'k shaft. It will be noted that the frame. 15 is cut away around the bolt 36 and thep'in'38 so that this pin may pivot to be passed throug-h -the opening 35 in the end-of the lever arm, The opening '35 :is of greater area on the inside of the arm than itis on the outside surface so that the bolt 36 may be readily passed therethrough. i I

The invention contemplates broadly the quick clamping and releasing of thecrankarm to a crank shaft and which crankarm may or may not be provided with a counterweight assembly.

What is claimed as new is:

-1. A'crank arm for wellpumping including a frame,- a clamping lever: connected thereto and extending along one-side thereof, anv opening for-med by-a part of said am;,andsaidlever-to receive the crank shaft, and means to lock said lever to the side of-said frame-to clamp said frame to thecrankshaft for rotation.-

A crank arm ccmprisingawrist pin receiving portion,,a-f-rame extending "therefrom which is V enlarged to; form a counter weight, and means to clamp said frame to the crankshaft including'a lever todraw the crank-arm againstthe crankshaft-.. V Q

--3; A combination crankarm and counterbalance weight for well-pumping includingaframe ofsubstantially triangular configuration, a lever pivoted to -the-apex of-;' said-frame, a recess in one of the sides of said frame to receive the crankshaft, said lever being adapted to'overlie said recess, and means'todraw *saidlever against the side; of, the frame to*-clamp the crankshaft in said recess. i

4.; counterbalance frame adapted for attachment to a crank shaft, a socket to receive the crank shaft, =a clampingslever pivoted to ,said

frame' adiacentsaid socket and shaped tojcoopere, ate with said frame to encircle the crankshaft;

said klever being of g a :length to extend along. said frame and be clamped thereto;

5. A counterbalance frame "adapted forattachment to a crank-shaft, a socketto receive the crank shaft, a-clamping lever pivoted to' said frame adjacent said socket and shaped to co,-

- operate with-said frame to encircle the crankshaft, said lever;being-ofa-lengthto extend along said frame and serve asa hoist to elevate said frametoposition said-crankshaftin said socket.

"6. A crank arm counterbalance frame including' 'a' crankarm-portion, a counterbalance portion, and an attaching portion, said attaching portion including a; recess to receive the crankshaft anda lever to be passed {over the crankshaft and to draw said frame into contact with the crank shaft.

.fRGBERT-BOYDDUNLAP. 

